Human Pancreatic Tumor Growth Hormone-Releasing Factor: Dose-Response Relationships in Normal Man

Human pancreatic GRF (hpGRF-40; 1 µg/kg, iv) selectively stimulates GH release in normal men (9). We now report the effects of graded doses of hpGRF-40 on GH release in 12 normal men. Mean peak increments in serum GH after vehicle and the various doses of hpGRF-40 were 1.13, 11.40, 14.60, 17.01, 14.45, and 15.60 ng/ml after vehicle and 0.1, 0.33, 1.0, 3.3, and 10 µg⁄kg hpGRF-40 (iv bolus), respectively. Peak values were observed 30–60 min after hpGRF-40 treatment. There was considerable variability of responsiveness among individual subjects, and no dose-response relationship between the doses and maximal GH values was found. However, the higher doses of 3.3 and 10.0 µg/kg resulted in a more prolonged and biphasic pattern of GH release. A side effect of facial flushing of less than 5-min duration occurred in 4 or 6 subjects who received 3.3 µg/kg andin all 5 who received 10 µg/kg of hpGRF-40. No changes in serum glucose, LH, TSH, PRL, plasma cortisol, or 8 enteropancreatic hormones occurred after hpGRF-40...